One of Britain's most senior doctors has warned people not to get ill because the situation in the NHS is so bad.

Sir Richard Thompson, President of the Royal College of Physicians, told Sky News a funding crisis is putting doctors under so much pressure it is putting patients at risk.

When asked where things were headed, Sir Richard said: "I'd rather not think about it. It's already (a) tremendous strain. When people ask me what’s going to happen I say don't get ill."

He also warned the health service is "underfunded by billions".

Sir Richard told Sunrise the NHS is "between a rock and a hard place", having to cope with an increasing population at the same time there is a shortage of doctors and nurses.

"The workload is going up at the same time money is being taken out of the NHS," he said, adding some smaller hospitals were already under "tremendous strain" to try and keep going.

"Because nurses and doctors are rushed they know that they can't produce good care."

Sir Richard claims doctors are missing patients' vital signs

Sir Richard added: "If you're not able to give an optimum time to looking after patients, the right number of staff looking after them, there must be some damage."

In an earlier interview with the Guardian, he claimed some doctors are facing caseloads during one shift of up to 70 patients - far more than the maximum 20 regarded as necessary for proper care.

Sir Richard said: "You try standing on your feet for seven hours trying to be on the ball, thinking of the various complications, being nice to patients, for seven hours. It's absolutely destructive.

"Not everyone has 70, but most people are looking after well over 20.

"If you've got over 20 it becomes impossible. The care gets thinner and thinner. It means the consultant can't see the patient as much or indeed as early as they should do, so obviously the standard of care is going to fall."

Sir Richard accused the coalition of cutting the NHS budget despite repeated pledges, including from Prime Minister David Cameron, to protect it from the austerity programme.

"In spite of what weasly words people at the top say, money's been taken out of the NHS," he said, citing the £2.8bn that has been given to social care in the past three years.

As a result, he claimed: "The NHS is under-doctored, under-nursed, under-bedded and under-funded. There are too few doctors to do the increasingly large job to a high standard, and safely, and compassionately."

A Department of Health spokesman responded by saying: "Patient safety and care is a priority for the Government and it is right that we have high expectations for our NHS.

"While the NHS is one of the safest, most efficient healthcare systems in the world we should never shy away from trying to improve standards for patients."